Buoyancy vests have become increasingly popular as a convenient means for a scuba diver to control his rate of ascent and descent. When such buoyancy vests were first used, the lung power of the diver was used to inflate the vest through a non-return valve while a manipulation of the non-return valve was used to open the valve to deflate the vest. For that purpose, the vest was provided with a large inflation tube with a combined mouthpiece and check valve at the end. The Koehn et al patent illustrates a composite mouthpiece readily attached to the distal end of the inflation hose in place of the conventional mouthpiece. The composite device includes a push valve and coupling to the high pressure source of breathable gases for powered inflation. Deflation by means of mere valve opening is slow and incomplete.
It has been proposed to utilize a Venturi device for aspirating the vest air. This device utilizes a complicated operating mechanism wherein both the exhaust valve and the inlet valve are simultaneously operated to achieve power deflation. This is cumbersome and somewhat unnatural. Other disadvantages exist: the control unit mounted at the end of the inflation tube is bulky and unmanageable; the jet thrust of escaping air adds to the instability.
The primary object of the present invention is to provide an improved, easy to operate and stable mechanism for power inflation and deflation of the buoyancy vest.